1) What is Photosynthesis? Explain the Mechanism of
Photosynthesis in Detail?
Answers
Answer:
Photosynthesis is a process by which carbondioxide is taken by the plants in the presence of sunlight and oxygen is realeasd.
It is a oxidation reduction reaction.
In photosynthesis process phototrophs are convert light energy into chemical energy which is later stored in the form of sugars, which are created from water and carbon dioxide. The by product of photosynthesisprocess is oxygen.
Answer:
The process of which Green plants containing Chlorophyll produce Food Materials (Glucose and Starch) from Carbon Dioxide (CO2), Water (H2O) using Light as a source of Energy and releases Oxygen (O2) into Atmosphere.
The Mechanism of Photosynthesis:
-> There are two phases of Light:
(i) LIGHT DEPENDENT REACTION: In this reaction, Light plays a key role. A series of chemical reactions occurs in a every quick succession initiated by Light and therefore this phase is called as Photochemical Phase or Dependent Reaction.
-> The Light reaction takes place in Chlorophyll containing Thylakoids called Grana of Chloroplasts. Several Steps occur in this Dependent reaction.
-> STEP 1: This Chlorophyll on exposure to light, energy becomes activated by absorbing Photons. (Photons the Smallest Unit of Light)
-> STEP 2: The energy is used in Splitting the Water molecules into two components Ions named Hydrogen (H+) and Hydrxyl (OH-).
→ H2O -----> (H+) + OH
-> The reaction is known as Photolysis which means Spillting by Light. [Photo means Light, and Lysis means Breaking].
-> This Process was discovered by Robert Hill. Hence this is also known as Hill's Reaction.
-> STEP 3: The highly reactive Ions of Water (H2O) and Oxygen (O2). Water (H2O) maybe used by the Plants and Oxygen (O2) is usually released into the Atmosphere.
-> Compunds that can drop energy like Adenosine Tri Phospahte (ATP) and Nicotinamide Adenosine Dinucleotide Phosphate Hydrogen (NADPH) are formed at the end of the Light reaction.
(ii) LIGHT INDEPENDENT REACTION: This rection does not require the presence of Sunlight and extension of the phases after day time may occur in some Plants and sometimes even in the Dark.
-> This reaction is known as the Light Independent Reaction or Biosynthetic phase.
-> But the term Dark Reaction doesn't mean that this reaction occur in Dark which is Night. It only means that it doesn't need the Presence of Sunlight.
-> (H+) Ions produced in Photolysis are immediately picked up by special compound NADP to form NADPH.
-> In the Dark phase of Hydrogen of the NADPH is used to combine it with by utilizing ATP energy and to produce Glucose.
-> This synthesis occurs in a number of shapes using certain special intermediate compond mainly RUBP (Ribulose Bis Phosphate) and Enzymes.
→ Finally the Glucose is converted into Starch.